From patchwork Thu Jan 16 06:04:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11336139 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 376FE92A for ; Thu, 16 Jan 2020 06:04:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 171FD207E0 for ; Thu, 16 Jan 2020 06:04:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729792AbgAPGE0 (ORCPT ); Thu, 16 Jan 2020 01:04:26 -0500 Received: from mx2.suse.de ([195.135.220.15]:45194 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729718AbgAPGE0 (ORCPT ); Thu, 16 Jan 2020 01:04:26 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 39DDCB1A3 for ; Thu, 16 Jan 2020 06:04:24 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v6 4/5] btrfs: Reset device size when btrfs_update_device() failed in btrfs_grow_device() Date: Thu, 16 Jan 2020 14:04:03 +0800 Message-Id: <20200116060404.95200-5-wqu@suse.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200116060404.95200-1-wqu@suse.com> References: <20200116060404.95200-1-wqu@suse.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org When btrfs_update_device() failed due to ENOMEM, we didn't reset device size back to its original size, causing the in-memory device size larger than original. If somehow the memory pressure get solved, and the fs committed, since the device item is not updated, but super block total size get updated, it would cause mount failure due to size mismatch. So here revert device size and super size to its original size when btrfs_update_device() failed, just like what we did in shrink_device(). Signed-off-by: Qu Wenruo --- fs/btrfs/volumes.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b899c8b0d0ee..6ba66c7cff2e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2805,6 +2805,7 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans, { struct btrfs_fs_info *fs_info = device->fs_info; struct btrfs_super_block *super_copy = fs_info->super_copy; + u64 old_device_size; u64 old_total; u64 diff; int ret; @@ -2815,6 +2816,7 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans, new_size = round_down(new_size, fs_info->sectorsize); mutex_lock(&fs_info->chunk_mutex); + old_device_size = device->total_bytes; old_total = btrfs_super_total_bytes(super_copy); diff = round_down(new_size - device->total_bytes, fs_info->sectorsize); @@ -2837,9 +2839,25 @@ int btrfs_grow_device(struct btrfs_trans_handle *trans, ret = calc_per_profile_avail(fs_info); mutex_unlock(&fs_info->chunk_mutex); if (ret < 0) - return ret; + goto out; - return btrfs_update_device(trans, device); + ret = btrfs_update_device(trans, device); +out: + if (ret < 0) { + /* + * Although we dropped chunk_mutex halfway for + * btrfs_update_device(), we have FS_EXCL_OP bit to prevent + * shrinking/growing race. + * So we're safe to use the old size directly. + */ + mutex_lock(&fs_info->chunk_mutex); + btrfs_set_super_total_bytes(super_copy, old_total); + device->fs_devices->total_rw_bytes -= diff; + btrfs_device_set_total_bytes(device, old_device_size); + btrfs_device_set_disk_total_bytes(device, old_device_size); + mutex_unlock(&fs_info->chunk_mutex); + } + return ret; } static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset)